Immunoglobulin M Deficiency Workup

Updated: Jul 19, 2018
  • Author: Iftikhar Hussain, MD; Chief Editor: Michael A Kaliner, MD  more...
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Laboratory Studies

Quantitative levels of IgM, IgG, IgA, and IgE, along with IgG subclasses, are measured. This is done to exclude more common immunodeficiency disorders, such as common variable immunodeficiency and IgA deficiency. Particularly in adults, serum immunoelectrophoresis should be done to rule out the possibility of a concomitant clonal B-cell disorder such as multiple myeloma or chronic lymphocytic leukemia.

The biological significance of a seemingly isolated low IgM level may be assessed by immunizing the patient with protein (eg, tetanus) and polysaccharide (eg, unconjugated Streptococcus pneumoniae) vaccines and assessing whether antigen-specific IgG responses are normal.


Imaging Studies

Imaging studies are not required routinely for SIgM deficiency. However, if patients report a history of recurrent sinopulmonary infection, CT scans of the sinuses and chest may be helpful for diagnosing chronic sinusitis and bronchiectasis, respectively.


Other Tests

Flow cytometry for B cells with surface IgM may be helpful.

Other tests are not required routinely for SIgM deficiency. However, other tests may be needed for further evaluation of associated diseases.



Diagnostic procedures are not routinely required for SIgM deficiency. They may be needed for diagnosis of infections, complications, or associated diseases.